Is it possible to config linux filesystem use fixed character encoding (like NTFS use UTF-16 internally) to store file names regardless of LANG/LC_ALL environment?

Or, what I actually want ask is: Is it possible to let file name 中文.txt ($'\xe4\xb8\xad\xe6\x96\x87.txt') in zh_CN.UTF-8 environment and file name 中文.txt ($'\xd6\xd0\xce\xc4.txt') in zh_CN.GBK environment refer to same file?

If it's not configurable, then is it possible to patch kernel to translate character encoding between file-system and current environment (just a question, not request implementation)? and how much performance con effect if it's possible?

You could tackle the problem from the Windows side by using Cygwin 1.7, which does automatically translate between the filesystem's UTF-16 encoding and whatever encoding has been specified in the locale settings. It defaults to UTF-8, so for example Cygwin tar would encode filenames as UTF-8.
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ak2Jun 24 '11 at 8:13

@ak2 Thanks, Cygwin is really good, I've been use it for years. The tar/zip case is just an example, in real environment, the zip/tar files may be created by others (such as download a file from internet).
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LiuYan 刘研Jun 24 '11 at 8:34

2 Answers
2

I have reformulated your questions a bit, for reasons that should
appear evident when you read them in sequence.

1. Is it possible to config linux filesystem use fixed character encoding to store file names regardless of LANG/LC_ALL environment?

No, this is not possible: as you mention in your question, a UNIX file
name is just a sequence of bytes; the kernel knows nothing about
the encoding, which entirely a user-space (i.e., application-level)
concept.

In other words, the kernel knows nothing about LANG/LC_*, so it cannot
translate.

2. Is it possible to let different file names refer to same file?

You can have multiple directory entries referring to the same file;
you can make that through hard links or symbolic links.

Be aware, however, that the file names that are not valid in the
current encoding (e.g., your GBK character string when you're working
in a UTF-8 locale) will display badly, if at all.

3. Is it possible to patch the kernel to translate character encoding between file-system and current environment?

You cannot patch the kernel to do this (see 1.), but you could -in
theory- patch the C library (e.g., glibc) to perform this translation,
and always convert file names to UTF-8 when it calls the kernel, and
convert them back to the current encoding when it reads a file name
from the kernel.

A simpler approach could be to write an overlay filesystem with FUSE,
that just redirects any filesystem request to another location after
converting the file name to/from UTF-8. Ideally you could mount this
filesystem in ~/trans, and when an access is made to
~/trans/a/GBK/encoded/path then the FUSE filesystem really accesses
/a/UTF-8/encoded/path.

However, the problem with these approaches is: what do you do with
files that already exist on your filesystem and are not UTF-8 encoded?
You cannot just simply pass them untranslated, because then you don't
know how to convert them; you cannot mangle them by translating
invalid character sequences to ? because that could create
conflicts...

Personally, I wish there's only 1 charset encoding (UTF-8) in the world, but there're legacy application still running, and interoperability between Windows and Linux must be achieved, most people must face this nightmare.
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LiuYan 刘研Jun 22 '11 at 18:38